光伏发电系统MPPT二阶滑模控制

摘要

Based on the mathematical model of photovoltaics,and the Boost booster circuit is adapted as the key link,its performance has important significance for maximum power point tracking(MPPT) of photovoltaic cells and improving work effficiency.Under the traditional controllers of MPPT,it is usually not easy to obtain a satisfactory control performance for photovoltaic power generation to large disturbances.Aiming at this problem,a chattering-free MPPT controlmethod based on the second order sliding mode control is proposed to improve the robustness of system.The control design is accomplished by designing a discontinuous second-order sliding mode controller where the derivative of the duty ratio is regarded as a virtual controller.The actual controller is the integration of the discontinuous second-order sliding mode controller,and thus the chattering problem can be avoided.Finally,the reliability and superiority of the chattering-free sliding mode controller are verified by simulation and experiment.The results show that under the disturbances of temperature and light,the response speed of the system become much faster and more stable.%基于光伏电池数学模型,采用Boost升压电路作为系统前端,其性能对光伏电池最大功率点跟踪(MPPT)、工作效率提高有重要意义.针对传统MPPT控制方法,在干扰较大的情况下,很难取得满意控制效果的问题,利用二阶滑模控制技术,提出一种无抖振的滑模控制方法,以改善大扰动情况下系统的鲁棒性.将占空比变量的导数视为虚拟控制器,设计非连续的二阶滑模控制器;实际控制器则为非连续控制器的积分,从而避免了控制器的抖振.仿真和实验结果表明光照强度和温度改变的情况下系统响应速度加快,且更加稳定.